The activity of neurons in the lateral intraparietal area (LIP) of the monkey predicts the monkey's allocation of spatial attention as determined by an increase in contrast sensitivity. We show here that despite being relatively high within the visual hierarchy, neurons in LIP have extremely short and precise visual latencies. Mean latency was 45.2 ms; the timing precision of the onset response was usually better than 4 ms. The majority of neurons had a pause in response following an initial burst, followed by more sustained visual activity. Prior attentional allocation had no effect on either the latency or magnitude of the initial burst, but produced clear effects on the magnitude of the later sustained activity. In contrast, stimulus characteristics influenced latency in a manner similar to that demonstrated in lower visual areas. Taken together, these data indicate that the initial burst in the LIP visual response reflects an uncontaminated sensory signal. Information about stimulus onset is transmitted rapidly through the visual system to LIP; we speculate that this pathway goes from V1 to LIP via area MT. The speed and temporal precision of the on-response is much higher than previously realized, consistent with the growing idea that timing precision is not diminished at successive stages of visual processing. A coincidence detector could look at the precisely-timed onset of activity from LIP neurons and detect the onset of a visual stimulus. If the activity across LIP is used to allocate attention, this would allow a quick and reliable orienting of attention to novel stimuli in the visual environment, a trait that would be evolutionarily advantageous.